As far as I know, the “when” only matters if you are after tender leaves that aren’t bitter. For the tea mentioned above, it doesn’t matter when you harvest the roots or the leaves, and it is probably a good idea to harvest all year round because if your child, or children, actually are coming down with their childhood diseases, you’d better have a nice large stock of dried roots and leaves.

If you want to read more about the usage of dandelion leaves, roots and seeds, both as an herbal remedy and as a nutritious addition to your diet, try this site:
http://www.living-foods.com/articles/dandelion.html

Rose

It does, and if you look at the “bronchitis” tag, you will find more herbal remedies for bronchitis that are safe for children, such as a mustard plaster, thyme compresses, or marjoram and oregano tea.

Rose